Telegraph system.



B. F. THOMESDH. TELEGRAPH SYSTEM. Ammonium FILED 920,22, 1910.

fimntedi Aug. 11, 191% 4 SHEETS-SHEET 1.

B. 'P. TEGMPSOBL TELEGRAPH SYSTEM.

ArPLIGATIQN TILED 1120.22, 1910.

ha r i g? B. F. THOMPSON.

TELEGRAPH SYSTEM.

.APBLIOATION TILED DEG.22,1910.

hmfifimu Patented Au 11, 19 14.

4 SHEETS-SHEET 3.

B. P. THOMPSGN. TELEGRAPH SYSTEM. APPLICATION FILED DBO. 22 I 1910.

Patented Aug. 13,1914;

i SHEETS-SHEBT 4.

WITNESSES Mr devi BEll'Jl-LIVIIN FRANK THOIYIPSON, F ARLINGTON, IVEXaIt'YLilI-TD.

TELEGIEMDE'H LiltllLTlSQ Specification of Letters Patent.

H 4-1 A .1 ni men too A .Qrpjglication filed December 22, 1910. Serial No. 538.6941.

To all 1011 0172 it may concern Be it known that l, BENJAMIN FRANK 'lnonrson, residing at Arlington, in the county of Baltimore and State of lllrn'ylsi'id have invented certain new and useful linprovenients in Telegraph Systems, of which the following is a specification.

This invention relates broadly to an nrprorcd system for transmitting intelligence between distant points, and more particularly to an improved system whereby at least two messagesmay be sent simultaneously over a single line conductor.

' One of the principal objects of the invention is to provide a system oi the above character whereby balancing of the line may be eliminated.

Another object is to provide a system coniprising terminal and plurality of intermediate stations whereby at least two messages may be transmitted between an y two of said stations without interference.

Another object of my invention is to pro vide a system oil. the above indicated character such that branch may be taken oil at any point along the line A further object is to provide s system whereby any station along the line may transmit single, duplex, or diplex signals thereo'ver.

The invention accordingly cons sts in the ieat-uresof construction, combinations of elements and arrangements of ports which will be exemplified in the description hereinafter set forth, and the scope of the application of which will be indicated in the appended claims.

In the accompan ing drawings which are to be taken as a part of this specification I have illustrated several of the preferred embotliments of my invention.

in these drawings, lfiigure 1 illustrates a system showing}; the same wire used both a through or terulincl station, and also a waystation wire; illustrates a system, comprising a plurality stations whereby certain of the stations may be grouped to the exclusion of other stations; Fig. 3 is a, view of the system, showing the line as comprising a terminal and a divided or branch line station; Fig. 4 illustrates a difl ercnt embodiment of the terminal apparatus from that disclosed in 3; Fig. wiles modified form oi the a'ogmrolus ticularity the instrinnentalities her in shown 'or carrying out my invention, it may here be noted that I combine means for iinpres, ing on the line an alternating current of the desired frequency, an d means for separating the positive halt waves of this current from the negative halt waves with sigiuiling a1?- paratus (herein shown as telegraph), such that certain oi the apparatus is operated by half wares 01 one polarity and the other an pm'atus by the half waves of opposite polarity.

Referring now to the drawings and par ticularly to the embodiment of my invention shown in Fig. l, A indicates one terminal station of a telegraphic circuit constr cted in accordance with this embodiment of my invention. 1 indicates o source of alternating current, the some being indicated dis.- graniniatically as an alternating current generator. This generator is interposed between ground 2 and the line Leading from line 3 are wires 4 and 5 respectively, each oi? (l and 'l tifier 8 11'1 Sllttll of rectifying; devices 8 and 9. BBC- the present instance, is connected a way as to 'transl'nit the. negative half of the alternating current Wave, and rectifier 9 connected to transmit the positive hall of the alternating current Wave. Leading from the terminal 10 of the rectifier 8 is a wire 11 which connects with the coil 12 of the telegraphic relay 13. Leading from coil 12 is the wire 14 connected with the ordinary telegraphic key 1, which cooperates with the contact 16 to close the circuit. The key provided "with the side switch 17 as is usual. in telegraphic practice. lit will be understood, of course, that the key 15 may be interposed to. any point between the wire 3 and the line wire 18 which leads from the contact 16. 19 indicates a locnl circuit which includes the source of current or battery 20 and the telegraphic sounder 21 said circuit being adapted to be closed by the armature of the relay 13 in the usual manner of telegraphic apparatus. It will therefore be understood that the engagement of the Key 15 with the contact 16 will cause the negative half of the alternating current wave to pass through the rectifier 8, relay l3, and key 15 to the line wire 18; thence to ground in a manner l crcirm'l" i l l l which is connected with terminalspolarized relay may be substituted therefor. The positive half of the alternating current wave passes through the wire 22 to the coil of the telegraphic relay 23, thence through the wire 24, key 25, contact 26, line wire 18, as will be understood from the description hereinbefore given with regard to the positive half of the alternating current wave, and operates the telegraphic sounder 27 in a manner which will be readily understood. Located in the other terminal B of this system is apparatus similar to that described in station A, the negative half of the alternating current wave passing from the wire 18'through the wire 28, rectifier 35, coil of the relay 32, wire 33, key 30, contact 29, wires 36 and 37 to ground.' Rectifier 35 is so connected in the line as to transmit only the negative half of the wave received over the line wire 18. Similarly, the rectifier--38 which is interposed between the line wire 18 and ground is connected in the line to transmit only the positive half of the alternating current wave, such wave operating the relay 39 to close the local circuit 40 in a manner which will be understood. The intermediate station C, which may be one of several interposed in the line wire 18 in this embodiment, is provided with telegraphic apparatus operated by only one-half of the alternating current wave, the remaining half of said wave being shunted around the telegraphic apparatus by means of the wire 85, which wire includes the rectifier 86 so connected in said shunt as to permit passage ,of the negative half of the alternating current wave. Any leakage through the rcctifiers 51 or 86 is taken care of by the rectifier 52 in a bridge connected with the wire between the rectifier 51 of the tele graphic apparatus and the rectifier 86 and the continuation of the line wire 18. One advantage of this arrangement of the system is that one-half of the alternating cur rent wave is so utilized that it operates as a way line, the other half being utilized as a direct line and connecting the terminal stations A and B.

By means of the construction and arrangement of the various instrumentalities which comprise the system above described, it will be understood that two messages may be transmitted simultaneously from station A to station B or "from station B to station A, or that single messages may be transmitted in opposite directions from either of said stations.

(*onsideringr. now, lilig. 2 of the drawings, A and it imlicate the terminal stations. 0 and 1) indicate two of various intermediate stations which may be interposed between the terminal stations in the line wire 18.

The wire 18 is connected at either end with ground and provided with a source of alternati i' current supply herein indicated-by the generator .1. In this embodiment of the invention, the telegraphic relay 87 responds to the negative half of the alternating current wave, the positive half thereof being shunted around this relay as by means of the wire 88, which includes the rectifier 89 so connected therein as to permit the passage of the positive half of the wave. The telegraphic relay 90 in station C is connected to respond to the positive half of the alternating current wave, the negative half being shunted around said relay as by means of the wire 91, and the rectifier {)2 which is connected therein, to permit the passage of the negative hall of the alternating current wave. Similarly, telegraph relay 93 in, station I) is connected in the line to respond to the negative half of the alternating current wave, the opposite half being taken care of by rectifier 9-1 included in the shunt 95. The apparatus in station B corresponds to that in station C, and is arranged to respond to the positive half of the alternating current wave. In the present embodiment it will be seen that stations A and D may communicate with each other simultaneously with a communication being carried on between the stations (3 and B. It will be obvious that a switch may be provided at any station by which the relay. and key at that station may be cut in series with the rectifier of opposite sign. This will permit an operator along the line to communicate with any station irrespective of the connection of'the apparatus to be called with the line.

' Referring now to the embodiment of my invention illustrated in Fig. 3, the appaa-atus in the station A is similar in all respects to that shown in station A in Fig. 1 of the drawings, and thereforethis apparatus will not he described herein, reference being made to the preceding part of the specification. Connected with the. line wire 18 are branch wires 59 and 60 respectively. Although it will be obvious that either of these wires might be considered a main line, and the other a branch thereof, for the purpose of this description, both pf these lines will be considered as branch. Branch 59 is connected through the rectifier 61, which separates out the negative half of the alternating current wave, with the coil of the telegraphic relay 62, which when operated closes the local circuit 63 throu h the sounder 6 t in the usual manner. T e wire 65 which leads from the coil of the telegraphic relay 62 is connected with the key (36 which coiiperates with the contact, (37. llxtending from contact G'kis a continuation of the branch line wire 59, said wire leading to a station herein designated at B". The apparatus in this station is similar to the apparatus in the station designated G" except that no rectifier is required. Both stations work upon the negative half of the division and current pulsation of the opposite sign only to be discharged through the other division, a bridge directly connecting the opposed members of each pair of opposed divisions, and rectifying means located in said bridge and so faced as to conduct to each side current pulsations of the Wrong sign which have leaked through the rectifying means of each division I 3. In a system of the class described, the combination with a line provided with a plurality of opposed divisions throughout its length, of a source of alternating current supply for said line, a plurality of signaling instruments located in each of said opposed divisions, rectifying means for supplying current pulsation of one sign through certain of said divisions and for supplying current pulsation of the opposed sign through the others of said divisions, the circuits through said divisions being normally closed, means associated with each instruhave leaked through the rectifying means of each di ision.

e, In a system of the class described, the combination W lth a line, of a source of alternating current supply for said line, a plurality of signaling instruments in said line arranged to respond to current pulsations of different signs, rectifying means for allowing current pulsations of one sign to be discharged through the instruments responsive to that sign, rectifying means for allowing current pulsations to be discharged through signaling instruments responsive to the opposite sign, and means for discharging current pulsations of a sign opposed to that for which each ofsaid rectifying means is adapted to discharge through the signaling instruments associated therewith to their proper avenues of flow.

5. In a system of the class described, in combination with a line, a source of alternating current, a plurality of signaling instruments connected with said line, rectifying means for discharging current pulsations of one sign to certain of said instruments, rectifying means for diverting current pulsations of the opposite sign to the others of said instruments, and means for; diverting through their proper avenue of flow,-cui rent pulsations of the opposite sign leaking through said rectifying means.

pulsations of the opposite sign around said" instruments.

In Witness whereof I affix my signature in the presence of two witnesses.

BENJAMIN FRANK THOMPSON.

Witnesses .VVILLIAM E. HAnKNnss, A.. S. HoNiesBnne. 

